If this is your first time getting a set of bearings, it can be a bit confusing because you’re going to be faced with a number of brand options and choices, but don’t let it stress you. You can’t go wrong. Nearly all skateboard bearings have been standardized so that all wheel and bearing brands are compatible. The standard skateboard bearing size is an 8mm inner race diameter.
Having said that, there are a few things it would be helpful to know before you jump in.
What are ABEC Ratings?
If you’re buying your bearings online and not from a skate shop, one of the things you’ll see is the ABEC Rating. First off let’s clear up what ABEC actually means - Annular Bearing Engineering Committee, which is part of the American Bearing Manufacturers Association. These guys measure the tolerance and precision of bearings from a range of ABEC 1-9 and you’ll see ABEC ratings shown on almost all skateboard bearings, but a higher rating doesn't necessarily mean it is better for skateboarding.
There are many factors that are not included in the ABEC rating system, such as impact handling, lateral stress handling, materials, lubricant, noise, and vibration. A higher rating means a bearing has a capability for greater speeds, but even the world record speed on a skateboard is not fast enough for the ABEC rating to make difference in skateboarding roll speed.
TIP: The best skateboard bearings are clean, well-oiled bearings. If you want to go fast, keep ‘em clean!
What are Skateboard Bearings Made of?
STEEL
Steel bearings are the industry standard and are both durable and economical. The quality of the steel can vary. Higher grade steel in premium bearings can make the bearing faster and more durable. The downside of steel is its tendency to rust when exposed to moisture. If you want your bearings to last, keep them well-oiled avoid rolling through puddles or skating in the rain. If you do get them wet, drop in some extra lube, keep rolling or put them by a heater to dry them quickly.
CERAMIC
Ceramic bearings are harder than steel and deform less when pressure is applied to them. Since they are also heat resistant, they expand less and create less friction at faster speeds. Another benefit is that they do not rust when exposed to moisture, making them great for cruisers. The only downside to ceramic bearings is that ceramic itself is a brittle substance. The ceramic is susceptible to breaking if skated under high impact, meaning ceramic bearings are great for commuting and low impact skating, but not ideal for jumping big gaps or stair sets.
TIP: While the balls in ceramic bearings cannot rust, the steel races still can. They’ll be more resilient, but you should still avoid water when possible.
TITANIUM
Titanium is lightweight, durable and highly rust resistant. Bearings made from titanium perform similar to steel bearings but can last longer due to titanium's strength and resistance to corrosion. Like steel bearings, keep titanium bearings lubricated to reduce excess friction.
SKATEBOARD BEARING PARTS
Now that you know the different kind of bearings, it would be good to familiarize yourself with what makes up a bearing.
BALLS
A set of six to seven balls roll freely along a track formed by the races and are held in place by the retainer. The rotating and rolling balls are the crux of how the bearing works. Less balls means less friction and more speed.
INNER AND OUTER RACES
The races form the track for the balls to roll, and also create the inner and outer walls of the bearing.
RETAINER
The retainer keeps the balls in place, equal distances from each other to reduce friction in increase strength.
SHIELDS
Shields cover the sides to help protect the balls from dust and debris. Some bearings have shields that are removable for easier cleaning. Some have one or zero shields for reduced friction.
BEARING SPACERS
Some sets of bearings come with bearing spacers. They are small cylindrical pieces that fit on the axle, between the bearings in the core of the wheel. These spacers are meant to keep your bearings properly aligned and allow you to fully tighten your axle nut without restricting the spin of the wheel. They are optional for most types of skating.
TIP: If you want to powerslide on soft wheels, bearing spacers will reduce vibrations and make your slides much smoother and easier to control.